{"product_id":"australian-boulder-opal-stone-1501","title":"Boulder Opal Cut Stone – 10.54ct, Semi-Dark, Blue \u0026 Green Flash","description":"\u003cstyle\u003e.rotr-faq { border-bottom: 1px solid #e5e5e5; padding: 14px 4px; margin: 0; } .rotr-faq:first-of-type { border-top: 1px solid #e5e5e5; } .rotr-faq \u003e summary { cursor: pointer; font-weight: 600; list-style: none; display: flex; justify-content: space-between; align-items: center; padding: 4px 0; outline: none; } .rotr-faq \u003e summary::-webkit-details-marker { display: none; } .rotr-faq \u003e summary::after { content: \"+\"; font-size: 1.5em; font-weight: 300; line-height: 1; margin-left: 12px; transition: transform 0.2s ease; } .rotr-faq[open] \u003e summary::after { content: \"−\"; } .rotr-faq-answer { margin: 10px 0 0 0; }\u003c\/style\u003e\n\n\u003cp\u003eThis is a loose, unset solid boulder opal from Quilpie in South West Queensland — ready for a collector's cabinet or to be taken straight to a jeweller for a custom setting. It weighs 10.54 carats and measures 18×15mm, cut to a free-form shape that follows the natural contours of the stone. The body is semi-dark, deep enough to give the colour real contrast without reading heavy. Across that background, blue dominates — a clean, saturated flash that shifts as the stone moves — with a secondary flash of green that rolls in from different angles. The ironstone matrix is intact on the back, just as nature left it. One stone, no treatments, no enhancements.\u003c\/p\u003e\n\n\u003ch3\u003eAbout Boulder Opal\u003c\/h3\u003e\n\u003cp\u003eBoulder opal forms as veins of precious opal within ironstone matrix in the opal fields of Queensland — primarily Quilpie, Yowah and Winton. Unlike black opal from Lightning Ridge, the opal cannot be separated from its host rock; it's cut as a single solid piece, with the natural brown ironstone remaining as the stone's backing. This gives boulder opal its distinctive look — vivid colour against rich earth tones — and also makes it physically more durable than other opals, since the ironstone host is harder than the opal layer it carries.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStone:\u003c\/strong\u003e Solid Boulder Opal\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCarat Weight:\u003c\/strong\u003e 10.54ct\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 18×15mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eColour Play:\u003c\/strong\u003e Blue with green flash\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBody Tone:\u003c\/strong\u003e Semi-dark\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrightness:\u003c\/strong\u003e Medium\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Free-form \/ natural\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOrigin:\u003c\/strong\u003e Quilpie, Queensland\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAvailability:\u003c\/strong\u003e One-of-a-kind — 1 stone available\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCaring for Your Opal\u003c\/h3\u003e\n\u003cp\u003eOpal is softer than diamond or sapphire, so a little care goes a long way. See \u003ca href=\"\/pages\/opal-care\"\u003eOpal Care\u003c\/a\u003e for storage, cleaning, and what to avoid.\u003c\/p\u003e\n\n\u003ch3\u003eProvenance\u003c\/h3\u003e\n\u003cp\u003eHand-selected by Joseph Bernecki, sourced direct from the Australian opal fields and set in his Sydney workshop. Meet him any weekend at The Rocks Market, stall under the bridge, Sydney. \u003ca href=\"\/pages\/about-rocks-on-the-rocks\"\u003eRead Joseph's story →\u003c\/a\u003e\u003c\/p\u003e\n\n\u003ch3\u003eCommon Questions\u003c\/h3\u003e\n\u003cdetails class=\"rotr-faq\"\u003e\u003csummary\u003eCan this stone be set into jewellery?\u003c\/summary\u003e\u003cdiv class=\"rotr-faq-answer\"\u003eYes — that's exactly what it's built for. Joseph can set it into a pendant, ring, or brooch in his Sydney workshop; just get in touch and he'll talk you through options and quote a price. Alternatively, take it to your own jeweller — boulder opal works well in bezel and partial bezel settings that protect the edge while keeping the face open to the light.\u003c\/div\u003e\u003c\/details\u003e\n\u003cdetails class=\"rotr-faq\"\u003e\u003csummary\u003eWhy does boulder opal have brown on the back?\u003c\/summary\u003e\u003cdiv class=\"rotr-faq-answer\"\u003eThe brown material is the natural ironstone host rock — it's not a backing that's been added. Boulder opal forms inside ironstone boulders in Queensland, and the opal layer can't be separated from it without destroying the stone. The ironstone stays on as part of the piece, which is why boulder opal is considered a solid natural stone even though it looks layered. It also makes the stone tougher than a thin polished opal slice would be on its own.\u003c\/div\u003e\u003c\/details\u003e\n\u003cdetails class=\"rotr-faq\"\u003e\u003csummary\u003eCertification, shipping, returns?\u003c\/summary\u003e\u003cdiv class=\"rotr-faq-answer\"\u003eEvery piece is backed by Joseph's personal guarantee, ships fully insured within Australia, and can be returned within 14 days. See \u003ca href=\"\/pages\/buying-an-opal\"\u003eBuying an Opal\u003c\/a\u003e for the full breakdown.\u003c\/div\u003e\u003c\/details\u003e","brand":"Rocks On The Rocks","offers":[{"title":"Default Title","offer_id":43656383266999,"sku":"1501","price":850.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0051\/9176\/1987\/files\/2024_06_10_0451.jpg?v=1728044485","url":"https:\/\/www.rocksontherocks.com\/products\/australian-boulder-opal-stone-1501","provider":"Rocks On The Rocks","version":"1.0","type":"link"}